This application is based upon Japanese Patent Application No. Hei. 11-184236 filed on Jun. 29, 1999, the contents of which are incorporated herein by reference.
1. Field of the Invention:
The present invention relates to information display apparatuses, and particular to an information display apparatus which includes control means for controlling display means to display several kinds of information based on a program, and in which the control means interrupt the program so as to perform a restart process, when it becomes necessary to restart during executing the program; and relates to navigation apparatuses, and particular to a navigation apparatus for performing a guidance by means of displaying a route to a destination on display means based on present position data from a position sensor and map data by using control means.
2. Related Art:
In an information display apparatus such as a vehicular navigation apparatus, recently, a voice recognizing function, a 3D graphic function, or a communication function such as an Internet including VICS has been added. As a result, functions to be processed become too complicated, so that a CPU as control means needs to process huge amount of processes.
Furthermore, in a case where plural programs are executed at the same time, the program may enter an abnormal condition in which a normal operation is not secured during executing the program, depending on the executed process because of the following reasons. That is, an access to a memory and a writing of the data may conflict each other; or an access to an odd address, an access to a write-protected region, or an undefined interruption process, may occur.
In such a case, the CPU generally interrupts the program so as to restart. However, in a case of the vehicular navigation apparatus as shown in FIGS. 11A-11D, when the restart process is executed while a map is displayed as a result of executing a route guidance operation (see FIG. 11A), a map display condition is suddenly stopped and no (blank) picture is temporally displayed on a screen as shown in FIG. 11B, namely a black picture condition.
After that, when the program is reloaded and each of the initial setting operations are completed, an initial picture is displayed (see FIG. 11C), both the present position data and the map data are inputted as a result of executing the program, and the present position is additionally displayed on the map, so as to return a condition before the restart.
However, it takes long time to execute several initializing process by the CPU of the control circuit or execute an initializing process of several input/output devices being connected, similar to the initial (first) startup just after a power is turned on. Therefore, it takes a constant time (10 seconds or more) to start to display a picture, because the picture is displayed on the display unit after these processes are completed.
When such the restart process is suddenly started, a user, who does not recognize the executing of the restart process, may feel that the apparatus may be broken down. Incidentally, a user, who recognizes the start of the restart process, needs to wait relatively long time to restore.
The present invention has been conceived in view of the above background, and its first object is to provide an information display apparatus and a navigation apparatus each of which can reduce a restore time needed for restoring a display condition as much as possible.
Its second object is to provide an information display apparatus and a navigation apparatus each of which can reduce a restore time needed for restoring a display condition as much as possible when it becomes necessary to restart a program while displaying information, by appropriately omitting several initializing processes during a starting-up.
According to one aspect of the present invention, during a restart process of the program, display control means read display picture information at restart timing from storing means and display it on display means. Therefore, it prevents the display means from becoming no display condition even in the restart process and can continuously display a picture. When it needs certain time to complete the restart process, a time needed to restore the display condition can be reduced as much as possible, it can prevent user""s incongruity feeling, and it does not take long time to start to display.
According to another aspect of the present invention, when it becomes necessary to restart of the program, the control means interrupt the program so as to execute the restart process. Here, since the initializing process for external inputting means is generally completed at the first startup process, the restart process omits this process to start up in a short time. Thus, it can prevent the user from waiting for a long time equal to that of the first start up, under a condition that the display means display no picture.
According to still another aspect of the present invention, a navigation apparatus operates so that control means perform guidance by displaying a route to a destination on the display means based on present position data from a position sensor and map data. Here, when it becomes necessary to restart of the program during executing the route guidance based on the program, the control means interrupt the program so as to perform the restart process. During a restart process, display control means read display picture information at restart timing from storing means and display it on display means. Therefore, it can prevent the display means from becoming no display condition. For the user, since it can prevent the inconvenience that the display means suddenly become no display condition and the user has to wait until the startup condition, the user will not be worried during the route guidance and the user does not have to wait for long time until displaying.